1. Technical Field
The present disclosure relates to communication within a digital processing system and more specifically to bus based communications with a peripheral controller in such digital processing systems.
2. Related Art
Digital processing systems contain buses to provide communication between various components such as processors, memory elements, and peripherals. Buses are contained within digital processing systems (shorter distance) and contain an express arbiter to allocate the bus to one of the components for transmission. Peripheral Controller Interface (PCI), Serial Peripheral Interface (SPI), SATA (Serial Advanced Technology Attachment) are some example standards defining the operation of corresponding buses, as is well known in the relevant arts.
Buses are contrasted with paths forming basis for networks (connecting digital processing systems) in that such network paths (span long distance) are provided external to digital processing systems and do not have an express arbiter. Instead the common path is shared by relying on distributed techniques such as CSMA/CD (one of the systems takes control of the network first for transmission in a given time duration) or token ring (each system is provided a turn to transmit).
Peripheral controllers are often employed in digital processing systems to facilitate communication with external devices (peripherals). A peripheral controller is a component which interfaces with (has a physical interface attached to) a bus on one side and with the external devices on the other side to facilitate communication between components interfacing with the bus and the external devices. The peripheral controller may be implemented to support the specific communication protocols and other interface requirements, for the bus as well as for individual one of the external devices, to facilitate such communication.
In general, it is desirable that such communications between components (interfacing with a bus) and the external devices be provided while meeting one or more of requirements such as reduced overhead for the components and/or peripheral, the duration of usage of the bus, etc.
In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.